A comparison of geostationary-orbiting satellite IR images and polar-orbiting microwave images (from the CIMSS Tropical Cyclones site) for each of the 3 tropical cyclones are shown below. Note that there is a 1-2 hour difference between the IR images and the microwave images — however, these comparisons show the utility of the microwave images for showing tropical cyclone structures that are often masked by the cold convective cloud shield.

Tropical Storm Karl: geostationary IR image + polar microwave image

Hurricane Igor: geostationary IR image + polar microwave image

Hurricane Julia: geostationary IR image + polar microwave image

An AWIPS image of EUMETSAT METOP Advanced Scatterometer (ASCAT) winds (below) indicated surface winds as high as 63 knots near the center of Hurricane Igor at 13:28 UTC; however, ASCAT winds are known to have a low speed bias (which increases as winds get to higher speeds).

EUMETSAT METOP ASCAT winds

As part of the GOES-15 Post Launch Science Test, the satellite was placed into Rapid Scan Operations (RSO) mode, providing images as frequently as every 5 minutes during the day. The evolution of the eye of Hurricane Igor is seen on GOES-15 0.63 Âµm visible channel images (below; also available as a QuickTime movie) — note the occasional presence of small mesovortices within the eye region.